Compounds having a fluorene skeleton (for example, 9,9-bisphenylfluorene skeleton) are known to have excellent functions in terms of optical properties such as light transmittance and refractive index and thermal properties such as heat resistance. Therefore, compounds having a fluorene skeleton are used as raw materials for optical members such as lenses, prisms, filters, image display materials, optical disk substrates, optical fibers, optical waveguides, casing materials, films, and coating materials. Such compounds having a fluorene skeleton include, for example, compounds disclosed in Patent Literature 1.
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2011-201791